Parents' perspectives on dried blood spot self-sampling from children with epilepsy: A mixed-method study.

AIM: Children with epilepsy often have concomitant diagnoses. Dried blood spot samples for drug monitoring can be collected by parents at home as an alternative to traditional sampling. This mixed-method study aimed to understand the parents' perspectives on blood self-sampling from their children and to identify factors contributing to successful sampling. METHOD: Parents who had collected a sample from their child during a visit to the neuropediatric clinic were asked to fill in a questionnaire. To get in-depth information and individual perspectives, parents and nurses participated in semi-structured interviews and analysed with thematic analysis. RESULTS: The results from questionnaires (n = 64) and interviews (n = 9) were interpreted together. Watching an instruction video and practical training contributed to successful sampling. 97% of the parents managed to collect a sample, 72% thought it was easy to perform, and 80% found self-sampling at home desirable. Factors for success were as follows: high motivation, prepared parents with pre-understanding, a pragmatic attitude, flexible education, effective communication and willingness to take on the role as a performer. Risk factors were as follows: conflict, fear, unprepared parents, confused or worried children. CONCLUSION: Voluntary self-sampling at home for parents of children with epilepsy is feasible and can reduce stress factors in everyday life.

Dried Blood Spot Self-Sampling by Guardians of Children With Epilepsy Is Feasible: Comparison With Plasma for Multiple Antiepileptic Drugs.

BACKGROUND: Dried blood spot (DBS) is an attractive matrix alternative to plasma for the measurement of antiepileptic drug concentrations with the possibility of self-sampling at home. The aim of this study was to evaluate whether DBS concentrations from a children population could be used as an alternative to plasma concentrations in a clinical routine laboratory. METHODS: Children with epilepsy using carbamazepine (CBZ), lamotrigine (LTG), levetiracetam (LEV), or valproic acid (VPA) had capillary blood collected for routine plasma analysis. DBS samples were collected by guardians or nurses, and the quality of sampling was compared between the groups. DBS samples were analyzed with liquid chromatography-tandem mass spectrometry methods and plasma samples with immunochemical methods. In the comparison between DBS and plasma concentrations, previously analyzed sample data were pooled with data in this study and resulted in 190 comparison pairs. A bioanalytical cross-validation according to European Medicines Agency was performed. Clinicians evaluated the results to understand if a DBS concentration was linked to a different clinical dose recommendation for the patient in comparison with plasma concentrations. RESULTS: Comparison of DBS sample quality showed that 2.3% of the capillary DBS collected by guardians were rejected and 8.0% of the capillary DBS collected by nurses. For DBS, a conversion factor of 0.85 for CBZ and 1.65 for VPA was applied for the comparison with plasma. LTG and LEV results were directly comparable. In the cross-validation, 88% of CBZ, 75% of LTG, 74% of LEV, and 94% of VPA comparisons were within 20% of the difference of the mean, although LEV had a few major differences (+31% to -40%). In 4 of the 190 comparisons, the clinical evaluation indicated a risk of conflicting decisions regarding the need for dose adjustment when using DBS concentrations. However, the risk of negative patient outcomes was considered negligible. CONCLUSIONS: Our study demonstrates that a combination of bioanalytical cross-validation and clinical evaluation is an effective way to describe the applicability of DBS as an alternative to plasma, taking into account how therapeutic drug monitoring is used in specific patient groups. For LTG, converted CBZ and VPA, DBS is a feasible alternative for self-sampling at home. DBS for LEV can only be recommended for nonadherence queries due to the high variability of the plasma/DBS concentration ratios.